Film and method for the production of colored pictures



Nov.. 25, 1924 %17,049

` J. H. CHRISTENSEN FILM ND METHOD FOR THE PRODUCTION OF COLOREDPICTURES Filed Sent. 6. 1919 Purcus films c //////x///// a`*W//l/l//l/l///////////////////////////////////// reducing agents.

' tures.

.pictures.

` Diamiue !ast red F v ia dianisidie And-rosophenine S.

JENS HERM AN CHRISTENEN, OF HO TE, ?ai l `1". i

rimu: AND mrrnon ron. THE rnoDUcrIoN-or coto rx'c'r ::a

Application' filed September 6, 1819. Serial 1%.322328.

To all 'whomit may concern:

Be it known that I, JEN's HERMAN CHRIS- TENSEN, a subject of the King ofDenmark,

residing at Holte; Denmark, have invented a new and useful Improvementin Films and Methods for the Production of Colored Pictures; and I dohereby .declare the following to be a full, clear, and exact descriptionof the same. 4

This invention relates to photography and particularlyto photographicfilms i and methods i It has been proved that the finely divided silverin an exposed and developed photographicfilm has a special catalyticeffect on the action of reducingiagents on certain dyes, which withoutthe presence of this catalyzer can only with difliculty or only at ahigh temperature be bleached through According to the invention inis.crrcumstance is taken advantage of for producing colored photographicpic- In the accompanying drawing Figs. 1 to 4 illustrate various stepsin the practice of the invention. r

If for instance a silver bromide-gelatifne plate is dyed with a dye thatis readily bleached. in the presence of a catal st, ex-

d (4)Pheno1,1. (4 reetor and Congo-Reinblau which is Tolidine tetrazotehaving acid H. where acd H means:

1.8 amidonaphthol 3.6 disulpho aeid.

which (1) salicylic aeid t fi-amlnoaphtbol sul ho acid 2:83, in acidaolt on (2 a-naphthol sulphoacid N. w. 1:4

:Bomoazurlne o which 1 fPrimuline+a-naphthol sulpho Qera raw.

i which is the late' being either soaked in a solution of t is dye orthe emulsion bein 'colored before the coating, and ifsueh' a p ateisexposerl in a photographic 'camera or othe.'-.

wse an ordnary black silver'picture in a eolored gelatine filmisobtained after de-' 'hydrosulphite, 'stannous for the production ofcolored "ers rduc'er. Most of the dyes adapted for the pur ose' silverbefore 2 molecules of ip' o-nsphthol Bulpho ecid N. w. 1:4 j

sensitizecl for colored lightand lie directl .posed sensitive b fixing.Through 'subsequent treatment with apowerful reducing agent such assodium been proved that the dye is bleached in such places of the filmas contain 'silver and the 'degree of bleaching-- is dependent onthequantity of the silver so that a picture' with half-tones is obtained''A 1-3% solution of sodium hydrosulphite may be used. When the bleachingis finished the silver can be dissolved and removed by known means suchas ehromic acid, so-called Farmer's reducer etc. so that a clear colorpicture remains.

Instead'of as described above', developing picture with onereducingagentand thereafter bleaching with another reducirg 'agent, the reducton ofthe silver and the bleaching of the dye can be efifected in oneoperation. The developin and bleaching can for instance be eifecte bymeans of thefollowing solution: I v

1 00 parts of water. I

2 parts of sodium hydrosulphite.

2 parte of potassium bromide.

-Thereafter the silver as well as the silver bromide can be removed bymeans of Farmbelongto the so-called' dianile des ome dyes give a betterresult when t'e reduced the treatment with the bleachin well knownmanner is transformed into another compound, i. e. is; toned. Some dyes'are thus escially well bleached when the' silver' picture in wel-l knownmanner s to'ned to a Prussian ing re'ducing agent bluepicture and whenthe hydrosulphite sov lution is made alkaline.

By arranging two or more of the said coloredtsenstive films on eachother or on opposite sides of a celluloid film stve films' may be in asuitable manner on eachother or' be separated from eac other by suitableporous films, it is direct 'exposure .or by printing 'color-ed. ictureto produce a pture n more colors. us the method is a producing of copiesfrom color plates.

In the annexed drawing Fig. 1 'shows a section through e carrier@ and tupg tive and con wrW simultaneously which senchlorite etc. it haspossible 4 of a adapted for-& 'e

a greenish blue dye, c is green sensitive and and d is only bluesensitive and contains a yellow dye.

Figure 2`shows the same 'films separated by porous films e and fconsisting for in stance of porous celluloidor hardened gelatine;

Figure 3 shows one sensitiv-e film on each side of the carrier andfinally Figure 4 shows two films on one side of the carrier separated bya porous film c and u directly and need one film b on the other side.

The carrier a in Figures ?rand 4 i'ut be transparent which is notnecessarily the case with the carrier a in Figures 1 and 2.

Some'of the said dyes color the gelatine no mordanting. With others, amordanting is -desirable, in precipitating the dye in the film withmetal salts in known manner.

Having thus fully described my inventon I claim as new and desire tosecure by Let-- ters Patentz 1. The method of producing coloredphotographic pictures by bleachin'g. consistng in exposing a silverhalide gelatne film containing a dye which can be bleached by means of are ucing agent, developing the Same and catalytically bleaching at leastI In as contain silver after development.` 2. The' method of producingcolored photographic pictures by blea'ching consisti ing in exposing asilver halide gelatine film containing a dye which can be bleached bymeans of a reducing agent; treatingI said fihn with a solution of ahydrosulp ite compound until at least part of .the dye is bleached inthese parts of the film in which the silver halide is reduced.

3. A sensitized photographic element conprising a film containing asilver halide and a substantial amount of a dye which will be blechedcatalytically by reducing agents Von places on the said film which afterdeveloping will contain silver.

4. -A sensitized photographic element comprising a film containing asilver halide and a substantial amount of a dianile dye which Will bebleached catalytically by reducing agents on places on the said filmwhich after developingwill contain silver.

In testimony whereof I have aflixed my signature in presence of twowitnesses.

J EN S HERMAN CHRISTENSEN. itnesses:

CEc L V. SCHOU, u C. V. Has'rnn'.

part of the said dye in such places of the, contains besides 'thesensitizer a purple dye fil

